The proposed research is intended to isolate, purify and characterize the fluoroacetate defluorinating enzyme systems present in the 105,000 x g supernatant subcellular fraction of rat liver and lung. The effects of glutathione depletion on the toxicity of fluoroacetate will be tested in light of the implication of glutathione as a cofactor in this defluorination reaction. Distribution and subcellular localization of the defluorinating enzyme in kidney, testes and brain will be determined for these organs of toxicological interest for aliphatic fluorocarbons. Induction of defluoroacetate or other haloacetic acids.